So-called LIN (local interconnect network) data buses are increasingly being used, in particular in vehicles, which are each provided between a central unit (master) and a plurality of control units (slaves) and, for example, serve for the transmission of commands for the actuation of a central locking system of the vehicle, of window regulators, for the opening and closing of the vehicle, etc.
In this connection, a respective command is available on the total data bus. The data bus is, however, an electrical lead which has to be protected against manipulation from outside. The leading of a data bus out of a vehicle (for example to a side mirror) thus in particular represents a safety risk. Non-authorized commands can namely be introduced from such an unprotected region of the data bus accessible from the outside which, for example, effect an opening of the central locking system or an actuation of the window regulators. A separate data bus could admittedly be used e.g. for the mirror adjustment or the data could be encoded. Solutions of this type would, however, be relatively cost-intensive.
Another potential means to prevent unauthorized commands and to ensure a corresponding protection from theft and break-in, might include guiding a respective separate data line from the master to a respective slave at risk of manipulation. Such an additional data line at the master module, however, brings along a relatively high hardware effort and software effort. In such a case, each LIN transceiver would thus have to be connected to a serial interface at the master or at a microcontroller associated therewith and the corresponding software would have to be worked through, which would require additional computer power for the microcontroller.